The final lecture in the Downtown Lecture Series on happiness is at 6:30 tonight at the Fox Theatre, 17 W. Congress St. Dan Russell, professor of philosophy, Center for Philosophy of Freedom at the University of Arizona, will talk about “Happiness — A Feeling or a Future?”

Doors open at 5:30 p.m. and the theater is expected to fill to capacity. Overflow seating will be available at UniSource Energy Corp., 88 E. Broadway, where the lecture will be streamed live on a large screen.

The lecture is free, but tickets are required and will be available beginning at 11 a.m. at the Fox Theatre box office. The tickets are likely to be gone by 5:30 p.m., so be prompt.

A live Q&A chat with Russell will take place at noon Friday. Readers may submit questions at any time after the lecture Wednesday. They will appear when they are being answered Friday.